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Documentation

There are two different connection implementation: one, the default, uses Promise and the other uses Callback, allowing for compatibility with the mysql and mysql2 API's. The documentation provided on this page follows Callback. If you want information on the Promise API, see the README.

Quick Start

Install the mariadb Connector using npm

$ npm install mariadb

You can then uses the Connector in your application code with the Callback API. For instance,

  const mariadb = require('mariadb/callback');
  const conn = mariadb.createConnection({host: 'mydb.com', user:'myUser', password: 'myPwd'});
  conn.query("SELECT 1 as val", (err, rows) => {
      console.log(rows); //[ {val: 1}, meta: ... ]
      conn.query("INSERT INTO myTable value (?, ?)", [1, "mariadb"], (err, res) => {
        console.log(res); // { affectedRows: 1, insertId: 1, warningStatus: 0 }
        conn.end();
      });
  });

Installation

In order to use the Connector you first need to install it on your system. The installation process for Promise and Callback API's is managed with the same package through npm.

$ npm install mariadb

To use the Connector, you need to import the package into your application code. Given that the Callback API is not the default, the require() statement is a little different.

const mariadb = require('mariadb/callback');

This initializes the constant mariadb, which is set to use the Callback API rather than the default Promise API.

Timezone consideration

It's not recommended, but in some cases, Node.js and database are configured with different timezone.

By default, timezone option is set to 'local' value, indicating to use client timezone, so no conversion will be done.

If client and server timezone differ, timezone option has to be set to server timezone.

  • 'auto' value means client will request server timezone when creating a connection, and use server timezone afterwhile.
  • To avoid this additional command on connection, timezone can be set to IANA time zone.

Connector will then convert date to server timezone, rather than the current Node.js timezone.

Callback API

The Connector with the Callback API is similar to the one using Promise, but with a few differences.

Base:

Connection:

Pool:

PoolCluster

Base API

createConnection(options) → Connection

  • options: JSON/String Uses the same options as Promise API. For a complete list, see option documentation.

Returns a Connection object

Creates a new connection.

The difference between this method and the same with the Promise API is that this method returns a Connection object, rather than a Promise that resolves to a Connection object.

const mariadb = require('mariadb/callback');
const conn = mariadb.createConnection({
      host: 'mydb.com', 
      user:'myUser',
      password: 'myPwd'
    });
conn.connect(err => {
  if (err) {
    console.log("not connected due to error: " + err);
  } else {
    console.log("connected ! connection id is " + conn.threadId);
  }
});

Connection options

Essential options list:

option description type default
user User to access database. string
password User password. string
host IP address or DNS of the database server. Not used when using option socketPath. string "localhost"
port Database server port number. Not used when using option socketPath integer 3306
ssl Enables TLS support. For more information, see the ssl option documentation. mixed
database Default database to use when establishing the connection. string
socketPath Permits connections to the database through the Unix domain socket or named pipe. string
compress Compresses the exchange with the database through gzip. This permits better performance when the database is not in the same location. boolean false
connectTimeout Sets the connection timeout in milliseconds. integer 10 000
socketTimeout Sets the socket timeout in milliseconds after connection succeeds. A value of 0 disables the timeout. integer 0
rowsAsArray Returns result-sets as arrays, rather than JSON. This is a faster way to get results. For more information, see Query. boolean false

For more information, see the Connection Options documentation.

Connecting to Local Databases

When working with a local database (that is, cases where MariaDB and your Node.js application run on the same host), you can connect to MariaDB through the Unix socket or Windows named pipe for better performance, rather than using the TCP/IP layer.

In order to set this up, you need to assign the connection a socketPath value. When this is done, the Connector ignores the host and port options.

The specific socket path you need to set is defined by the socket server system variable. If you don't know it off hand, you can retrieve it from the server.

SHOW VARIABLES LIKE 'socket';

It defaults to /tmp/mysql.sock on Unix-like operating systems and MySQL on Windows. Additionally, on Windows, this feature only works when the server is started with the --enable-named-pipe option.

For instance, on Unix a connection might look like this:

const mariadb = require('mariadb/callback');
const conn = mariadb.createConnection({ socketPath: '/tmp/mysql.sock', user: 'root' });
conn.connect(err => {
  //do something with connection
  conn.end();
});

It has a similar syntax on Windows:

const mariadb = require('mariadb/callback');
const conn = mariadb.createConnection({ socketPath: '\\\\.\\pipe\\MySQL', user: 'root' });

createPool(options) → Pool

Returns a Pool object,

Creates a new pool.

Example:

const mariadb = require('mariadb/callback');
const pool = mariadb.createPool({ host: 'mydb.com', user: 'myUser', connectionLimit: 5 });
pool.getConnection((err, conn) => {
  if (err) {
    console.log("not connected due to error: " + err);
  } else {
    console.log("connected ! connection id is " + conn.threadId);
    conn.end(); //release to pool
  }
});

Pool options

Pool options includes connection option documentation that will be used when creating new connections.

Specific options for pools are :

option description type default
acquireTimeout Timeout to get a new connection from pool in ms. integer 10000
connectionLimit Maximum number of connection in pool. integer 10
idleTimeout Indicate idle time after which a pool connection is released. Value must be lower than @@wait_timeout. In seconds (0 means never release) integer 1800
minimumIdle Permit to set a minimum number of connection in pool. Recommendation is to use fixed pool, so not setting this value. integer set to connectionLimit value
minDelayValidation When asking a connection to pool, the pool will validate the connection state. "minDelayValidation" permits disabling this validation if the connection has been borrowed recently avoiding useless verifications in case of frequent reuse of connections. 0 means validation is done each time the connection is asked. (in ms) integer 500
noControlAfterUse After giving back connection to pool (connection.end) connector will reset or rollback connection to ensure a valid state. This option permit to disable those controls boolean false

Pool events

event description
acquire This event emits a connection is acquired from pool.
connection This event is emitted when a new connection is added to the pool. Has a connection object parameter
enqueue This event is emitted when a command cannot be satisfied immediately by the pool and is queued.
release This event is emitted when a connection is released back into the pool. Has a connection object parameter

Example:

pool.on('connection', (conn) => console.log(`connection ${conn.threadId} has been created in pool`);

createPoolCluster(options) → PoolCluster

Returns a PoolCluster object,

Creates a new pool cluster. Cluster handle multiple pools, giving high availability / distributing load (using round robin / random / ordered ).

Example:

const mariadb = require('mariadb/callback');

const cluster = mariadb.createPoolCluster();
cluster.add("master", { host: 'mydb1.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave1", { host: 'mydb2.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave2", { host: 'mydb3.com', user: 'myUser', connectionLimit: 5 });

//getting a connection from slave1 or slave2 using round-robin
cluster.getConnection(/^slave*$/, "RR", (err, conn) => {
  conn.query("SELECT 1", (err, rows) => {
     conn.end();
     return row[0]["@node"];
  });
});

PoolCluster options

Pool cluster options includes pool option documentation that will be used when creating new pools.

Specific options for pool cluster are :

option description type default
canRetry When getting a connection from pool fails, can cluster retry with other pools boolean true
removeNodeErrorCount Maximum number of consecutive connection fail from a pool before pool is removed from cluster configuration. null means node won't be removed integer 5
restoreNodeTimeout delay before a pool can be reused after a connection fails. 0 = can be reused immediately (in ms) integer 0
defaultSelector default pools selector. Can be 'RR' (round-robin), 'RANDOM' or 'ORDER' (use in sequence = always use first pools unless fails) string 'RR'

Connection API

connection.query(sql[, values][, callback]) -> Emitter

  • sql: string | JSON An SQL string value or JSON object to supersede default connections options. If aJSON object, it must have an "sql" property. For example: {dateStrings:true, sql:'SELECT NOW()'}
  • values: array | object Placeholder values. Usually an array, but in cases of just one placeholder, it can be given as is.
  • callback: function Callback function with arguments (error, results, metadata).

Returns an Emitter object that can emit four different types of event:

  • error : Emits an Error object, when query failed.
  • columns : Emits when columns metadata from result-set are received (parameter is an array of Metadata fields).
  • data : Emits each time a row is received (parameter is a row).
  • end : Emits when the query ends (no parameter).

Sends query to the database with a Callback function to call when done.

In cases where the query returns huge result-sets, this means that all data is stored in memory. You may find it more practical to use the Emitter object to handle the rows one by one, to avoid overloading memory resources.

For example, issuing a query with an SQL string:

connection.query("SELECT NOW()", (err, rows, meta) => {
  if (err) throw err;
  console.log(rows); //[ { 'now()': 2018-07-02T17:06:38.000Z } ]
});

Using JSON objects:

connection.query({dateStrings:true, sql:'SELECT now()'}, (err, rows, meta) => {
  if (err) throw err;
  console.log(rows); //[ { 'now()': '2018-07-02 19:06:38' } ]
});

Placeholder

To avoid SQL Injection attacks, queries permit the use of a question mark as a placeholder. The Connector escapes values according to their type. You can use any native JavaScript type, Buffer, Readable or any object with a toSqlString method in these values. All other objects are stringified using the JSON.stringify method.

The Connector automatically streams objects that implement Readable. In these cases, check the values on the following server system variables, as they may interfere:

  • net_read_timeout: The server must receive the query in full from the Connector before timing out. The default value for this system variable is 30 seconds.
  • max_allowed_packet: Using this system variable you can control the maximum amount of data the Connector can send to the server.
// Sends INSERT INTO someTable VALUES (1, _BINARY '.\'.st', 'mariadb')
connection.query(
  "INSERT INTO someTable VALUES (?, ?, ?)",
  [1, Buffer.from("c327a97374", "hex"), "mariadb"],
  (err, result) => {
	if (err) throw err;
	console.log(result);
	//log : { affectedRows: 1, insertId: 1, warningStatus: 0 }
  }
);

You can also issue the same query using Streaming.

const https = require("https");
https.get("https://node.green/#ES2018-features-Promise-prototype-finally-basic-support",
  readableStream => {
    connection.query("INSERT INTO StreamingContent (b) VALUE (?)", [readableStream], (err, res) => {
       if (err) throw err;
       //inserted
    });
  }
)

Query Results

Queries issued from the Connector return two different kinds of results: a JSON object and an array, depending on the type of query you issue. Queries that write to the database, such as INSERT, DELETE and UPDATE commands return a JSON object with the following properties:

  • affectedRows: Indicates the number of rows affected by the query.
  • insertId: Shows the last auto-increment value from an INSERT.
  • warningStatus: Indicates whether the query ended with a warning.
connection.query(
  "CREATE TABLE animals (" +
	"id MEDIUMINT NOT NULL AUTO_INCREMENT," +
	"name VARCHAR(30) NOT NULL," +
	"PRIMARY KEY (id))",
  err => {
	connection.query("INSERT INTO animals(name) value (?)", ["sea lions"], (err, res) => {
	  if (err) throw err;
	  console.log(res);
	  //log : { affectedRows: 1, insertId: 1, warningStatus: 0 }
	});
  }
);

Result-set array

Queries issued from the Connector return two different kinds of results: a JSON object and an array, depending on the type of query you issue. When the query returns multiple rows, the Connector returns an array, representing the data for each row in the array. It also returns a meta object, containing query metadata.

You can formt the data results using the nestTables and rowsAsArray options. By default, it returns a JSON object for each row.

connection.query('select * from animals', (err, res, meta) => {
  console.log(res); 
  // [ 
  //    { id: 1, name: 'sea lions' }, 
  //    { id: 2, name: 'bird' }, 
  //    meta: [ ... ]
  // ]  
});

Streaming

connection.query("SELECT * FROM mysql.user")
      .on("error", err => {
        console.log(err); //if error
      })
      .on("fields", meta => {
        console.log(meta); // [ ... ]
      })
      .on("data", row => {
        console.log(row);
      })
      .on("end", () => {
        //ended
      });

connection.batch(sql, values [, callback])

  • sql: string | JSON SQL string value or JSON object to supersede default connections options. JSON objects must have an "sql" property. For instance, { dateStrings: true, sql: 'SELECT now()' }
  • values: array Array of parameter (array of array or array of object if using named placeholders).
  • callback: function Callback function with arguments (error, results, metadata).

callback either return an [[#error|Error]] with results/metadata null or with error empty and results/metadata

Implementation depend of server type and version. for MariaDB server version 10.2.7+, implementation use dedicated bulk protocol.

For other, insert queries will be rewritten for optimization. example: insert into ab (i) values (?) with first batch values = 1, second = 2 will be rewritten insert into ab (i) values (1), (2).

If query cannot be re-writen will execute a query for each values.

result difference compared to execute multiple single query insert is that only first generated insert id will be returned.

For instance,

  connection.query(
    "CREATE TEMPORARY TABLE batchExample(id int, id2 int, id3 int, t varchar(128), id4 int)"
  );
  connection
    .batch("INSERT INTO `batchExample` values (1, ?, 2, ?, 3)", [[1, "john"], [2, "jack"]], (err, res) => {
      if (err) {
        console.log('handle error');
      } else {
      console.log(res.affectedRows); // 2
      }
    });

connection.beginTransaction([callback])

  • callback: function Callback function with argument Error if any error.

Begins a new transaction.

connection.commit([callback])

  • callback: function callback function with argument Error if any error.

Commits the current transaction, if there is one active. The Connector keeps track of the current transaction state on the server. When there isn't an active transaction, this method sends no commands to the server.

connection.rollback([callback])

  • callback: function Callback function with argument Error if any error.

Rolls back the current transaction, if there is one active. The Connector keeps track of the current transaction state on the server. Where there isn't an active transaction, this method sends no commands to the server.

conn.beginTransaction(err => {
  if (err) {
    //handle error
  } else {
    conn.query("INSERT INTO testTransaction values ('test')", (err) => {
      if (err) {
        //handle error
      } else {
        conn.query("INSERT INTO testTransaction values ('test2')", (err) => {
          if (err) {
            conn.rollback(err => {
              if (err) {
                //handle error
              }
            });
          } else {
            conn.commit(err => {
              if (err) {
                //handle error
              }
            });
          }
        });
      }
    })
  }
});

connection.changeUser(options[, callback])

Resets the connection and re-authenticates with the given credentials. This is the equivalent of creating a new connection with a new user, reusing the existing open socket.

conn.changeUser({user: 'changeUser', password: 'mypassword'}, err => {
  if (err) {
    //handle error
  } else {
    //connection user is now changed.
  }
});

connection.ping([callback])

  • callback: function Callback function with argument Error if any error.

Sends a one byte packet to the server to check that the connection is still active.

conn.ping(err => {
  if (err) {
    //handle error
  } else {
    //connection is valid
  }
})

connection.end([callback])

  • callback: function Callback function with argument Error if any error.

Closes the connection gracefully. That is, the Connector waits for current queries to finish their execution then closes the connection.

conn.end(err => {
  //handle error
})

connection.reset([callback])

  • callback: function Callback function with argument Error if any error.

reset the connection. Reset will:

  • rollback any open transaction
  • reset transaction isolation level
  • reset session variables
  • delete user variables
  • remove temporary tables
  • remove all PREPARE statement

connection.isValid() → boolean

Returns a boolean

Indicates the connection state as the Connector knows it. If it returns false, there is an issue with the connection, such as the socket disconnected without the Connector knowing about it.

connection.destroy()

Closes the connection without waiting for any currently executing queries. These queries are interrupted. MariaDB logs the event as an unexpected socket close.

connection.pause()

Pauses data reads.

connection.resume()

Resumes data reads from a pause.

connection.serverVersion()

Returns a string

Retrieves the version of the currently connected server. Throws an error when not connected to a server.

  console.log(connection.serverVersion()); //10.2.14-MariaDB

Error

When the Connector encounters an error, Promise returns an Error object. In addition to the standard properties, this object has the following properties:

  • fatal: A boolean value indicating whether the connection remains valid.
  • errno: The error number.
  • sqlState: The SQL state code.
  • code: The error code.

Example on console.log(error):

{ Error: (conn=116, no: 1146, SQLState: 42S02) Table 'testn.falsetable' doesn't exist
  sql: INSERT INTO falseTable(t1, t2, t3, t4, t5) values (?, ?, ?, ?, ?)  - parameters:[1,0x01ff,'hh','01/01/2001 00:00:00.000',null]
      ...
      at Socket.Readable.push (_stream_readable.js:134:10)
      at TCP.onread (net.js:559:20)
    From event:
      at C:\mariadb-connector-nodejs\lib\connection.js:185:29
      at Connection.query (C:\mariadb-connector-nodejs\lib\connection.js:183:12)
      at Context.<anonymous> (C:\mariadb-connector-nodejs\test\integration\test-error.js:250:8)
    fatal: false,
    errno: 1146,
    sqlState: '42S02',
    code: 'ER_NO_SUCH_TABLE' } }

Errors contain an error stack, query and parameter values (the length of which is limited to 1,024 characters, by default). To retrieve the initial stack trace (shown as From event... in the example above), you must have the Connection option trace enabled.

For more information on error numbers and SQL state signification, see the MariaDB Error Code documentation.

events

Connection object that inherits from the Node.js EventEmitter. Emits an error event when the connection closes unexpectedly.

  const conn = mariadb.createConnection({user: 'root', password: 'myPwd', host: 'localhost', socketTimeout: 100})
  conn.on('error', err => {
    //will be executed after 100ms due to inactivity, socket has closed. 
    console.log(err);
    //log : 
    //{ Error: (conn=6283, no: 45026, SQLState: 08S01) socket timeout
    //    ...
    //    at Socket.emit (events.js:208:7)
    //    at Socket._onTimeout (net.js:410:8)
    //    at ontimeout (timers.js:498:11)
    //    at tryOnTimeout (timers.js:323:5)
    //    at Timer.listOnTimeout (timers.js:290:5)
    //  fatal: true,
    //  errno: 45026,
    //  sqlState: '08S01',
    //  code: 'ER_SOCKET_TIMEOUT' }
  });

Pool API

Each time a connection is asked, if the pool contains a connection that is not used, the pool will validate the connection, exchanging an empty MySQL packet with the server to ensure the connection state, then give the connection. The pool reuses connection intensively, so this validation is done only if a connection has not been used for a period (specified by the "minDelayValidation" option with the default value of 500ms).

If no connection is available, the request for a connection will be put in a queue until connection timeout. When a connection is available (new creation or released to the pool), it will be used to satisfy queued requests in FIFO order.

When a connection is given back to the pool, any remaining transactions will be rolled back.

pool.getConnection(callback)

Creates a new Connection object. Connection must be given back to pool with the connection.end() method.

Example:

const mariadb = require('mariadb/callback');
const pool = mariadb.createPool({ host: 'mydb.com', user:'myUser' });
pool.getConnection((err, conn => {
  if (err) {
    console.log("not connected due to error: " + err);
  } else {
    console.log("connected ! connection id is " + conn.threadId);
    conn.end(); //release to pool
  }
}));

pool.query(sql[, values][, callback])

  • sql: string | JSON SQL string or JSON object to supersede default connection options. When using JSON object, object must have an "sql" key. For instance, { dateStrings: true, sql: 'SELECT now()' }
  • values: array | object Placeholder values. Usually an array, but in cases of only one placeholder, it can be given as is.
  • callback: function Callback function with arguments (error, results, metadata).

This is a shortcut to get a connection from pool, execute a query and release connection.

const mariadb = require('mariadb/callback');
const pool = mariadb.createPool({ host: 'mydb.com', user:'myUser' });
pool.query("SELECT NOW()", (err, results, metadata) => {
  if (err) {
    //handle error
  } else {
    console.log(rows); //[ { 'NOW()': 2018-07-02T17:06:38.000Z }, meta: [ ... ] ]
  }
});

pool.batch(sql, values[, callback])

  • sql: string | JSON SQL string or JSON object to supersede default connection options. When using JSON object, object must have an "sql" key. For instance, { dateStrings: true, sql: 'SELECT now()' }
  • values: array array of Placeholder values. Usually an array of array, but in cases of only one placeholder per value, it can be given as a single array.
  • callback: function Callback function with arguments (error, results, metadata).

This is a shortcut to get a connection from pool, execute a batch and release connection.

const mariadb = require('mariadb/callback');
const pool = mariadb.createPool({ host: 'mydb.com', user:'myUser' });
pool.query(
  "CREATE TABLE parse(autoId int not null primary key auto_increment, c1 int, c2 int, c3 int, c4 varchar(128), c5 int)"
);
pool
  .batch("INSERT INTO `parse`(c1,c2,c3,c4,c5) values (1, ?, 2, ?, 3)", 
    [[1, "john"], [2, "jack"]],
    (err, res) => {
      if (err) {
        //handle error
      } else {
        //res = { affectedRows: 2, insertId: 1, warningStatus: 0 }
        assert.equal(res.affectedRows, 2);
        pool.query("select * from `parse`", (err, res) => {
            /*
            res = [ 
                { autoId: 1, c1: 1, c2: 1, c3: 2, c4: 'john', c5: 3 },
                { autoId: 2, c1: 1, c2: 2, c3: 2, c4: 'jack', c5: 3 },
                meta: ...
              }
            */ 
        });
      }
  });

pool.end([callback])

  • callback: function Callback function with argument (Error).

Closes the pool and underlying connections gracefully.

pool.end(err => {
  if (err) {
    //handle error
    console.log(err);
  } else {
    //connections have been ended properly    
  }
});

Pool events

event description
acquire This event emits a connection is acquired from pool.
connection This event is emitted when a new connection is added to the pool. Has a connection object parameter
enqueue This event is emitted when a command cannot be satisfied immediately by the pool and is queued.
release This event is emitted when a connection is released back into the pool. Has a connection object parameter

Example:

pool.on('connection', (conn) => console.log(`connection ${conn.threadId} has been created in pool`);

Pool cluster API

Cluster handle multiple pools according to patterns and handle failover / distributed load (round robin / random / ordered ).

poolCluster.add(id, config)

  • id: string node identifier. example : 'master'
  • config: JSON pool options to create pool.

Add a new Pool to cluster.

Example:

const mariadb = require('mariadb/callback');
const cluster = mariadb.createPoolCluster();
cluster.add("master", { host: 'mydb1.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave1", { host: 'mydb2.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave2", { host: 'mydb3.com', user: 'myUser', connectionLimit: 5 });

poolCluster.remove(pattern)

  • pattern: string regex pattern to select pools. Example, "slave*"

remove and end pool(s) configured in cluster.

poolCluster.end([callback])

  • callback: function Callback function with argument (Error).

Closes the pool cluster and underlying pools.

poolCluster(err => {
  if (err) {
    //handle error
    console.log(err);
  } else {
    //pools have been ended properly    
  }
});

poolCluster.getConnection([pattern, ][selector, ]callback)

  • pattern: string regex pattern to select pools. Example, "slave*". default '*'
  • selector: string pools selector. Can be 'RR' (round-robin), 'RANDOM' or 'ORDER' (use in sequence = always use first pools unless fails). default to the
  • callback: function Callback function with arguments (Error, Connection).

Creates a new Connection object. Connection must be given back to pool with the connection.end() method.

Example:

const mariadb = require('mariadb/callback');
const cluster = mariadb.createPoolCluster();
cluster.add("master", { host: 'mydb1.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave1", { host: 'mydb2.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave2", { host: 'mydb3.com', user: 'myUser', connectionLimit: 5 });
cluster.getConnection("slave*", (err, conn) => {
  //use connection and handle possible error
})

poolCluster events

PoolCluster object inherits from the Node.js EventEmitter. Emits 'remove' event when a node is removed from configuration if the option removeNodeErrorCount is defined (default to 5) and connector fails to connect more than removeNodeErrorCount times. (if other nodes are present, each attemps will wait for value of the option restoreNodeTimeout)

const mariadb = require('mariadb/callback');
const cluster = mariadb.createPoolCluster({ removeNodeErrorCount: 20, restoreNodeTimeout: 5000 });
cluster.add("master", { host: 'mydb1.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave1", { host: 'mydb2.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave2", { host: 'mydb3.com', user: 'myUser', connectionLimit: 5 });*
cluster.on('remove', node => {
  console.log(`node ${node} was removed`);
})

poolCluster.of(pattern, selector) → FilteredPoolCluster

  • pattern: string regex pattern to select pools. Example, "slave*". default '*'
  • selector: string pools selector. Can be 'RR' (round-robin), 'RANDOM' or 'ORDER' (use in sequence = always use first pools unless fails). default to the

Returns :

Creates a new filtered pool cluster object that is a subset of cluster.

Example:

const mariadb = require('mariadb/callback')

const cluster = mariadb.createPoolCluster();
cluster.add("master-north", { host: 'mydb1.com', user: 'myUser', connectionLimit: 5 });
cluster.add("master-south", { host: 'mydb1.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave1-north", { host: 'mydb2.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave2-north", { host: 'mydb3.com', user: 'myUser', connectionLimit: 5 });
cluster.add("slave1-south", { host: 'mydb2.com', user: 'myUser', connectionLimit: 5 });

const masterCluster = cluster.of('master*');
const northSlaves = cluster.of(/^slave?-north/, 'RANDOM');
northSlaves.getConnection((err, conn) => {
    //use that connection
});

filtered pool cluster

  • filteredPoolCluster.getConnection(callback) : Creates a new connection from pools that corresponds to pattern .
  • filteredPoolCluster.query(sql[, values][, callback]) : this is a shortcut to get a connection from pools that corresponds to pattern, execute a query and release connection.
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